Power Supply Inrush Current Limiting via Capacitor Switch Control

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Solution Overview

Problem

Conventional battery packs face issues with inrush currents during activation, which require additional configurations like inrush current limiting circuits, leading to increased power loss, complexity, and manufacturing costs.

Innovation Solution

A power supply device with a regulator, sensing unit, reference voltage controller, and a first switch that controls driving power, independent of the current flowing through the regulator, and includes a capacitor to remove noise, eliminating the need for separate inrush current limiting circuits by maintaining electrical connection even when the switch is off.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate inrush current limiting circuit is added to prevent inrush currents, then reliability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improveinrush current preventionVSAvoidcircuit configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the inrush current limiting function with the existing power supply circuit by using the capacitor that is already part of the power supply device. The capacitor naturally limits inrush current when the switch is turned on, eliminating the need for a separate inrush current limiting circuit while maintaining reliability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The capacitor in the power supply device serves multiple functions: it acts as both a noise filter and an inrush current limiter. By maintaining electrical connection between the capacitor and the switching element even when the switch is off, the capacitor continuously provides inrush current protection without requiring additional dedicated components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a separate inrush current limiting circuit is added, then reliability is improved, but power loss increases

Engineering Contradiction:

Improveinrush current preventionVSAvoidpower loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent merges the inrush current limiting function into the existing capacitor-based power supply circuit. The capacitor's natural charging behavior provides inrush current limitation without requiring additional resistive elements that would cause power loss, thus maintaining energy efficiency while improving reliability.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If a separate inrush current limiting circuit is added, then reliability is improved, but manufacturing cost increases

Engineering Contradiction:

Improveinrush current preventionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines inrush current protection functionality with existing power supply components (capacitor and switch). This integration eliminates the need for separate inrush current limiting circuits, reducing component count, simplifying assembly, and lowering manufacturing costs while maintaining reliable inrush current prevention.

Inventive Principle:

Principle #5Merging (Combining)

4Ease of operation

If the switch is completely disconnected from the capacitor, then ease of operation is improved, but reliability deteriorates due to loss of inrush current protection

Engineering Contradiction:

Improveswitch controlVSAvoidinrush current protection

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent maintains a permanent electrical connection between the capacitor and switching element, allowing the capacitor to continuously provide inrush current protection. The switching element controls power delivery to the load while the capacitor independently handles inrush current limitation, achieving both ease of operation and reliable protection.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Prevents inrush currents during activation, simplifies internal circuitry, reduces unnecessary power loss, and lowers manufacturing costs by eliminating the need for additional inrush current limiting configurations.

Implementation Method 1

a capacitor arranged between the input terminal and the regulator to remove noise included in the input power

Methodology Applied

Scientific EffectCapacitance filtering: Capacitance

Implementation Method 2

a regulator reducing a voltage of input power applied to an input terminal

Methodology Applied

Scientific EffectVoltage regulation:

Data Source

PatentUS11121566B2Power supply and battery pack including same

Publication Date: 2021.09.14 SAMSUNG SDI CO LTD

AI summary

The described technology relates to a power supply and a battery pack including the same. In one embodiments, the power supply includes an input terminal configured to receive input power, a regulator configured to reduce a voltage of the input power, and a sensing circuit configured to sense an output voltage of the regulator. The power supply also includes a reference voltage controller configured to receive the input power as driving power and to feedback-control the output voltage of the regulator to correspond to a preset reference voltage, based on the sensed output voltage. The power supply further includes a switch arranged between the input terminal and the reference voltage controller and configured to control the driving power applied to the reference voltage controller.